Barotrauma refers to injuries caused by increased air or water pressure, such as during airplane flights or scuba diving. Barotrauma of the ear is common. Generalized barotraumas, also called decompression sickness, affects the entire body.
Your middle ear includes the eardrum and the space behind it. The only connection between your middle ear and the "outside world" is a thin canal called the Eustachian tube. This connects your ear with the back of your mouth. When you swallow, you may notice a small click in your ears. This is a bubble of air being moved through the Eustachian tube. These bubbles are constantly moving into the middle ear, where they balance the ear's inner pressure. Ear barotrauma can occur when these tubes become blocked or partially blocked.
On an airplane, barotrauma to the ear – also called aero-otitis or barotitis – can happen as the plane descends for landing. Barotrauma of the ear also can happen when scuba divers descend. The pressure change can create a vacuum in the middle ear that pulls the eardrum inward. This can cause pain and can muffle sounds. Your ear will feel stuffed and you may feel as if you need to "pop" it.
In more severe cases of barotrauma, the middle ear can fill with clear fluid as the body tries to equalize the pressure on both sides of the eardrum. This fluid is drawn out of blood vessels in the lining of the inner ear, and can only drain if the Eustachian tube is open. Fluid behind the eardrum is called serous otitis media. It can create pain and hearing difficulty similar to a middle ear infection.
The eardrum can rupture (break) in severe cases of ear barotrauma, causing bleeding or leaking of fluid from the ear. A ruptured eardrum can result in hearing loss. In severe cases, it is possible for the pressure to create a leak between the deepest structures of the ear (the fluid-filled bony canals called the cochlea and semicircular canals) and the inner ear space. This deep leak is known as a fistula. If this occurs, the balance center can be affected, resulting in a sensation of spinning or falling called vertigo. This complication may require emergency surgery.
Barotrauma is the most common medical problem reported by air travelers. It is much more likely to happen to people who have colds, allergies or infections when they are flying. It is common in children because their Eustachian tubes are narrower than those of adults and become blocked more easily.
Barotrauma in the lungs also can occur, but this is not seen in air travelers. It occurs, rarely, in divers who hold their breath, when the diaphragm moves abruptly in a "gasping" effort. The diaphragm is the main muscle used in breathing. This form of barotrauma creates a vacuum in the lungs and can result in bleeding into the lung tissue. A more common form of barotrauma in the lungs is caused by the mechanical ventilation systems used in hospital intensive care units to help patients breathe. In this case, air sacks (alveoli) in the lungs may be ruptured or scarred due to high air pressure within the lungs. Ventilator-associated barotrauma is a complex medical concern.